diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/DataFlowInfo.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/DataFlowInfo.java
index 74ae0ee5a64..85ec913aa2f 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/DataFlowInfo.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/DataFlowInfo.java
@@ -201,4 +201,11 @@ public class DataFlowInfo {
         return !typeInfo.isEmpty();
     }
 
+    @Override
+    public String toString() {
+        if (typeInfo.isEmpty() && nullabilityInfo.isEmpty()) {
+            return "EMPTY";
+        }
+        return "Non-trivial DataFlowInfo";
+    }
 }
\ No newline at end of file